In the past, Patent Document 1 disclosed a decompression device in which an ejector is connected to a refrigerant outlet of a temperature type expansion valve, as a decompression device that is applied to a vapor compression refrigeration cycle.
In the decompression device disclosed in Patent Document 1, the pressure recovery of a refrigerant, which has been depressurization-boiled in a throttle passage of the temperature type expansion valve, is performed at an inlet of a nozzle portion of the ejector to generate boiling nuclei in the refrigerant flowing into the nozzle portion. Accordingly, the boiling of the refrigerant at the nozzle portion is facilitated, so that the reduction of nozzle efficiency is limited. Meanwhile, nozzle efficiency is energy conversion efficiency when the pressure energy of a refrigerant at the nozzle portion is converted into kinetic energy.